<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<html>
<head>
<!-- Copyright 1997 The Open Group, All Rights Reserved -->
<title>pthread_mutexattr_init</title>
</head><body bgcolor=white>
<center>
<font size=2>
The Single UNIX &reg; Specification, Version 2<br>
Copyright &copy; 1997 The Open Group

</font></center><hr size=2 noshade>
<h4><a name = "tag_000_007_1522">&nbsp;</a>NAME</h4><blockquote>
pthread_mutexattr_init, pthread_mutexattr_destroy
- initialise and destroy mutex attributes object
</blockquote><h4><a name = "tag_000_007_1523">&nbsp;</a>SYNOPSIS</h4><blockquote>
<pre><code>

#include &lt;<a href="pthread.h.html">pthread.h</a>&gt;

int pthread_mutexattr_init(pthread_mutexattr_t *<i>attr</i>);
int pthread_mutexattr_destroy(pthread_mutexattr_t *<i>attr</i>);
</code>
</pre>
</blockquote><h4><a name = "tag_000_007_1524">&nbsp;</a>DESCRIPTION</h4><blockquote>
The function
<i>pthread_mutexattr_init()</i>
initialises a mutex attributes object
<i>attr</i>
with the default value for all of the attributes
defined by the implementation.
<p>
The effect of initialising an already initialised mutex 
attributes object is undefined.
<p>
After a mutex attributes object has been used
to initialise one or more mutexes,
any function affecting the attributes object (including destruction)
does not affect any previously initialised mutexes.
<p>
The
<i>pthread_mutexattr_destroy()</i>
function destroys a mutex attributes object;
the object becomes, in effect, uninitialised.
An implementation may cause
<i>pthread_mutexattr_destroy()</i>
to set the object referenced by
<i>attr</i>
to an invalid value.
A destroyed mutex attributes object
can be re-initialised using
<i>pthread_mutexattr_init()</i>;
the results of otherwise referencing the object after it has been 
destroyed are undefined.
</blockquote><h4><a name = "tag_000_007_1525">&nbsp;</a>RETURN VALUE</h4><blockquote>
Upon successful completion,
<i>pthread_mutexattr_init()</i>
and
<i>pthread_mutexattr_destroy()</i>
return zero.
Otherwise, an error number is returned to indicate the error.
</blockquote><h4><a name = "tag_000_007_1526">&nbsp;</a>ERRORS</h4><blockquote>
The 
<i>pthread_mutexattr_init()</i>
function may fail if:
<dl compact>

<dt>[ENOMEM]<dd>
Insufficient memory exists to initialise the mutex attributes object.

</dl>
<p>
The
<i>pthread_mutexattr_destroy()</i>
function may fail if:
<dl compact>

<dt>[EINVAL]<dd>
The value specified by
<i>attr</i>
is invalid.

</dl>
<p>
These functions will not return an error code of [EINTR].
</blockquote><h4><a name = "tag_000_007_1527">&nbsp;</a>EXAMPLES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_007_1528">&nbsp;</a>APPLICATION USAGE</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_007_1529">&nbsp;</a>FUTURE DIRECTIONS</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_007_1530">&nbsp;</a>SEE ALSO</h4><blockquote>
<i><a href="pthread_create.html">pthread_create()</a></i>,
<i><a href="pthread_mutex_init.html">pthread_mutex_init()</a></i>,
<i>pthread_mutexattr_init()</i>,
<i><a href="pthread_cond_init.html">pthread_cond_init()</a></i>,
<i><a href="pthread.h.html">&lt;pthread.h&gt;</a></i>.
</blockquote><h4>DERIVATION</h4><blockquote>
Derived from the POSIX Threads Extension (1003.1c-1995)
</blockquote><hr size=2 noshade>
<center><font size=2>
UNIX &reg; is a registered Trademark of The Open Group.<br>
Copyright &copy; 1997 The Open Group
<br> [ <a href="../index.html">Main Index</a> | <a href="../xshix.html">XSH</a> | <a href="../xcuix.html">XCU</a> | <a href="../xbdix.html">XBD</a> | <a href="../cursesix.html">XCURSES</a> | <a href="../xnsix.html">XNS</a> ]

</font></center><hr size=2 noshade>
</body></html>

